Parse complete TypeSystemDefinition

tests/Language/GraphQL/AST/LexerSpec.hs

@@ -77,7 +77,7 @@ spec = describe "Lexer" $ do
             parse spread "" "..." `shouldParse` "..."
             parse colon "" ":" `shouldParse` ":"
             parse equals "" "=" `shouldParse` "="
-            parse at "" "@" `shouldParse` '@'
+            parse at "" "@" `shouldParse` "@"
             runBetween brackets `shouldSucceedOn` "[]"
             runBetween braces `shouldSucceedOn` "{}"
             parse pipe "" "|" `shouldParse` "|"

tests/Language/GraphQL/AST/ParserSpec.hs

@@ -109,3 +109,10 @@ spec = describe "Parser" $ do
               y: Float
             }
         |]
+
+    it "parses minimal input enum definition with an optional pipe" $
+        parse document "" `shouldSucceedOn` [r|
+            directive @example on
+              | FIELD
+              | FRAGMENT_SPREAD
+        |]